Lifting jack



Oct. 30, 1945- J. c. MCLAUGHLIN LIFTING- JACK Filed May 17, 1944 '2 Sheets-Sheet 1 Inventor fibm C M la Patented Oct. 30, 1945 UNITED STATES PATENT OFFICE LIETING JACK J ohn. Cl MbLaughlimDuluth, Minn. Application- May 1'7, 1944, Serial- No.535',969

3 Claims.

This invention relates to a novel and improved lifting jack which is especially, but not neces- -sarily, adapted to the job of lining up a propeller shaft in ocean vessels and the like.

The purpose of the invention is to provide a simple, substantial and relatively inexpensive shaft handling and aligning jack which is susceptible of accurate and reliable performance under temperature changes such as would otherwise afiect the accuracy of the alignment task.

' Briefly, the improved structure is characterized by an appropriate base, a perpendicular lifting or feed screw, novel means for adjustably mounting the screw in the base, a yoke atop the upper end of the feed screw, and shaft accommodating adapter and jaw means mounted for horizontal adjustment on said yoke, this to obtain the desired shifting and alignment of the shaft to be set in place and assembled.

Other features and advantages will become more readily apparent from the following description and the accompanying illustrative drawings.

In the drawings, wherein like numerals are employed to designate like parts throughout the same:

Figure 1 is a side elevational view of a special jack constructed in accordance with the structural principles of the instant invention.

Figure 2 is also an elevational view, this at right angles to Figure 1.

Figure 8 is a central vertical sectional view, with parts in elevation, taken approximately on the plane of the line 3-3 of Figure 1.

Figure 4 is an enlarged view at right angles to Figure 3, this on the plane of the line 4-4 of Figure 3.

Figure 5 is an end elevation of the shaft seating adapter unit or head.

Figure 6 is a section taken approximately on the plane of the line 6-6 of Figure 1, looking in the direction of the arrows.

Referring now to the drawings by distinguishing reference numerals it will be seen that the base proper is denoted by the numeral 1 and is a' flat bottom open frame-work design, the same being preferably provided with suitable handgrips 8 to facilitate placement and handling. The upper crown portion is fashioned into integral upstanding bearing 9 in which a bushing or sleeve I0 is swivelled for rotation. The lower end of the sleeve is reduced and screw-threaded as at H to accommodate an assembling and retaining nut l2. The sleeve is internally screw-threaded to accommodate the vertical lift or feed screw l3.

Also, a collar is formed at the top of the sleeve, said collar I4 resting rotatably on the end-thrust upper end of said bearing 9. In addition, the collar is provided with marginal sockets IE to accommodate a detachable tool rod (not shown) which is employed conveniently to rotate the sleeve in the bearing and to either elevate or lower the feed screw I3.

The aforementioned yoke I6 is securely fastened to the upper end of the feed screw, the arms thereof being provided with horizontally aligned named end extends out and is provided with a tool grip 20 to accommodate a'wrenph. The intermediate portion of the shaft is screw threaded as at 2! and operates through an internally screw-threaded bushing 22 carried in an eye-lug 23 provided on the central lower portion of the shiftable adapter unit 24. The latter has its body portion formed with keys or ribs 25 slida'ble in keyways provided in the upper ends of the yoke arms. The work-engaging faces or jaws are denoted by the numerals 26 and are of general V-shaped form, the faces converging to accommodate the shaft 21 or other parts to be shifted and lifted.

It is evident that this jack is of a double-acting type. That is to say, the feed screw I3 is raised and lowered through the instrumentality of the collar-equipped swivelled sleeve Ill. As before stated the rod or tool (not shown) is placed in a selected one of the sockets l5 to accomplish this adjustment of the feed screw. The work is seated between the jaws as shown in dotted lines in Figure 1 and may be shifted back and forth by the adjustable connection 2|, that is, the connection between the shaft I! and the bushing 22. Due to accuracy required in lining up shafts of the type mentioned it is evident that this vertical and horizontal or two-way adjustment feature is highly desirable, especially where temperature changes require the shaft to be bodily moved in a horizontal plane after the principal vertical adjustment is attained.

It is thought that persons skilled in the art to which the invention relates will be able to obtain a clear understanding of the invention after considering the description in connection with the drawings. Therefore, a more lengthy description is regarded as unnecessary.

Minor changes in the shape, size and arrangement of details coming within the field of inven tion claimed may be resorted to in actual practice, if desired.

Having described the invention, What is claimed as new is:

1. In a lifting and adjusting jack of the class described, a, base, a feed-screw adjustably mounted on said base, a yoke secured to the upper end of said feed-screw, said yoke having its arms provided with bearings and grooves forming keyways, a. horizontal. threaded shaft mounted in said bearings, an adapter unit comprising a body having shaft-accommodating jaws, said body being provided intermediate its'ends with a depending lug having a, screw-threaded bushing threaded on said shaft, said body having keys fitted in said keyways.

2. A lifting and adjusting jack of the class described, a base, a vertical feed screw adjustably mounted on said base, a yoke secured to the upper end of said feed screw, said yoke having its arms provided with bearings, a horizontal threaded shaft mounted in said bearings, an adapter unit comprising a body having shaft accommodating jaws, said body being provided intermediate its ends with a depending lug having a screwthreaded bushing threaded on said shaft.

3. A lifting and adjusting jack of the class described, a base, a vertical feed screw adjustably mounted on said base, a yoke secured to the upper end of said feed screw, said yoke having its arms provided with bearings and grooves forming keyways, a horizontal threaded shaft mounted in said bearings, an adapter unit comprising a body having shaft accommodating jaws, said body being provided intermediate its ends with a screw-threaded depending lug threaded on said shaft, said body also having keys fitted in said keyways. 

